1. Field of the Invention
The invention is directed to a device to measure strain wirelessly, referred to hereinafter as a “directly applied read and transmit-digital strain encoder” (DART-DSE).
2. Description of Related Art Including Information Disclosed under 37 CFR §§1.97 and 37 CFR 1.98
In the prior art as shown in FIG. 8, the sensor gage is a single, long, continuous circuit of thin foil. Strain is inferred from the change in electrical resistance over the entire length of the foil circuit. The strain field in the vicinity of the crack affects only a small fraction of the total sensing length. This indication is “averaged” with the remaining unaffected length, thereby degrading the signal near small strain fields created by precursors to structural problems.
The prior art sensor gage of FIG. 8:                Lacks sensitivity needed for structural health monitoring (“SHM”)        Must be thermally matched with the material of the underlying body        Can experience electrical drift on certain engineered materials (e.g. composites)        
It is to the solution of these and other problems that the present invention is directed.